Statement #1. “The value of NameNode new generation size should be 1/8 of maximum heap size (-Xmx). Please check, as the default setting may not be accurate.”

Statement #2. “To change the default value, edit the /etc/hadoop/conf/hadoop-env.sh file and change the value of the -XX:MaxnewSize parameter to 1/8th the value of the maximum heap size (-Xmx) parameter.”

Statement #1 indicates NameNode new generation size (NewSize) should be 1/8th the value of the maximum heap size.
Statement #2 indicates NameNode maximum new generation size (MaxNewSize) should be 1/8th the value of the maximum heap size.

I believe, Statement #1 is correct and sufficient. So, maybe Statement #2 should have said “the -XX:NewSize parameter” instead??? Thanks.